Bar versus ball attachments for maxillary four‐implant retained overdentures: A randomized controlled trial

• Published in: Clinical oral implants research Vol. 30; no. 11; pp. 1076 - 1084
• Main Authors: Park, Jin‐Hong, Shin, Sang‐Wan, Lee, Jeong‐Yol
• Format: Journal Article
• Language: English
• Published: Denmark Wiley Subscription Services, Inc 01.11.2019
• Subjects: Accessories; Bleeding; Bone loss; Clinical outcomes; Clinical trials; Complications; dental implant; Dental implants; Dental materials; Dental Prosthesis, Implant-Supported; Dentistry; Denture Retention; Denture, Overlay; Dentures; edentulous; Esthetics, Dental; Gingival index; Humans; Jaw, Edentulous; Maintenance; Maxilla; Mechanical loading; overdenture; Patient satisfaction; Patients; Plaque index; Prostheses; Randomization; randomized controlled trial; Statistical analysis; overdenture; edentulous; maxilla; dental implant; randomized controlled trial
• ISSN: 0905-7161; 1600-0501
• DOI: 10.1111/clr.13521

Objectives To compare the clinical treatment outcomes of maxillary four‐implant retained overdentures with either splinted (bar) attachments or non‐splinted (ball) attachments. Material and Methods Forty participants who were dissatisfied with their existing conventional maxillary complete dentures were included in this randomized controlled trial. Six months after implant placement, a definitive prosthesis was inserted. Implant success, condition of peri‐implant tissue, prosthodontic maintenance and complications, and patient satisfaction were assessed. Outcomes were recorded at baseline, prosthesis delivery, and at 3 and 12 months following prosthesis delivery, and a statistical analysis was performed. Results Thirty‐two of the forty patients completed the 1‐year follow‐up and had their treatment outcomes evaluated. The mean marginal bone loss after 1 year of loading was 0.34 ± 0.88 mm, and there were no significant differences between the two groups. Plaque index, gingival index and bleeding on probing were significantly higher in the bar group (p<.001), and the implant success rate of the bar group was significantly lower than that of the ball group (p=.028). The most frequent prosthodontic maintenance and complication issue was the need to change the bar clip or O‐ring as a result of retention loss. Patient satisfaction did not differ between the two groups except for aesthetics at 3 months. Conclusions Within the limitations of this study, the maxillary 4‐implant retained overdenture exhibited predictable results regardless of the attachment systems (ball or bar) in the 1‐year follow‐up period. The bar group was more vulnerable than the ball group with respect to maintaining peri‐implant tissue health.